Biodegradable cigarette filter

ABSTRACT

A biodegradable cigarette filter includes a first filter tube, a second filter tube and a wrap paper. The first filter tube and the second filter tube each has an essentially cylindrical shape and has an open end and a closed end, and is filled with organic fibers. The first filter tube and the second filter tube are placed adjacent to each other with their respective open ends facing each other, and the wrap paper wraps around at least part of the outside of the first filter tube and at least part of the outside of the second filter tube to hold the first filter tube and the second filter tube together. Methods for making a biodegradable cigarette filter are also described.

BACKGROUND

The present invention relates to a biodegradable cigarette filter. Conventional cigarettes typically have a substantially cylindrical rod shaped structure and include a charge, roll or column of smokable material, such as shredded tobacco (e.g., in cut filler form), surrounded by a paper wrapper, thereby forming a so-called “smokable rod” or “tobacco rod.”

Normally, a cigarette also has a cylindrical filter element aligned in an end-to-end relationship with the tobacco rod. The filter element is commonly made of cellulose acetate fibers bonded to each other by triacetin and circumscribed by a paper material known as a “plug wrap.” Certain filter elements can also incorporate polyhydric alcohols. Typically, the filter element is attached to one end of the tobacco rod using a circumscribing wrapping material known as “tipping paper.”

After smoking, the spent cigarette filters are often improperly discarded in the environment. The cellulose acetate filaments tend to degrade slower than tobacco and/or the paper parts of the cigarette, due to the highly entangled nature of the fibers, solvent bonding between the fibers, and the slow degradability of the cellulose acetate polymer. Typically, the time required for a cigarette filter to break down is 10-15 years, and it is estimated that every year worldwide approximately 4.5 trillion cigarette butts wind up as litter. It is estimated that about 30 percent of the waste along U.S. shorelines, waterways, and on land is made up by cigarette butts.

SUMMARY

A biodegradable cigarette filter includes a first filter tube, a second filter tube and a wrap paper. The first filter tube and the second filter tube each has an essentially cylindrical shape and has an open end and a closed end, and is filled with organic fibers. The first filter tube and the second filter tube are placed adjacent to each other with their respective open ends facing each other, and the wrap paper wraps around at least part of the outside of the first filter tube and at least part of the outside of the second filter tube to hold the first filter tube and the second filter tube together. Methods for making a biodegradable cigarette filter are also described.

Various embodiments can include one or more of the following advantages. Since the biodegradable cigarette filters are completely made of organic materials, they break down significantly faster than conventional filters, thereby having less impact on the environment compared to conventional cigarette filters. For example, there is less pollution around shorelines, waterways and on land, which is not only aesthetically pleasing but also reduces cleanup costs. A safer environment for animals is also created, that might otherwise ingest conventional plastic cigarette filters.

There may even be some degree of health benefits to smokers resulting from using the biodegradable cigarette filters. While smoking undoubtedly presents serious health hazards, a significant portion of these health problems result from tar and other chemicals entering the lungs of the smokers. The various embodiments of the biodegradable cigarette filters described herein may capture a larger amount of tar compared to conventional cigarette filters, and thereby reduce the amount of tar that ends up in the smoker's lungs. Thus, while smoking cessation is clearly the best way to address health issues related to smoking, a person who is not able to do this may still experience some reduced health hazards when smoking cigarettes that have a biodegradable filter in accordance with the various embodiments described herein. In addition, the biodegradable filters show a minimum reduction in flavor compared to conventional cigarette filters.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an empty filter tube and filter tube filled with fibers, respectively, in accordance with one embodiment.

FIG. 2 shows two filled filter tubes ready for assembly, in accordance with one embodiment.

FIG. 3 shows an assembled biodegradable cigarette filter, in accordance with one embodiment.

FIG. 4 shows a method for making a biodegradable cigarette filter, in accordance with one embodiment.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

The various embodiments of the invention described herein pertain to biodegradable cigarette filters, which will now be illustrated by way of example and with reference to the figures. In one embodiment, the materials needed for manufacturing a cigarette filter include organic fibers, filter paper, wrap paper and glue.

In accordance with one embodiment, the fibers are corchorus fibers, which are more commonly known as jute. Jute fibers are 100% biodegradable and produce no irritation to the skin. In fact, jute leaves are edible and its fibers are often used to make cloth that is used for clothing and other various purposes. Further, jute has low thermal conductivity, which makes it suitable for application in a cigarette filter where it is desirable not to conduct significant heat through the filter. However, as the skilled person realizes, jute is merely one type of fiber that could be used in cigarette filters, and various other types of organic fibers having similar properties can also be used. For example, in other embodiments, cotton might be used as an alternative to jute, and achieve similar efficacy. In yet other embodiments a combination of two or more kinds of organic fibers may be used.

In accordance with one embodiment, the filter paper is used to form cylindrical tubes into which the fibers can be packed. This will be described in further detail below. In order to use the filter paper for this purpose, the filter paper needs to be porous enough to allow air to flow through it, but at the same time dense enough to trap the fibers to prevent the fibers from entering the lungs of the smokers when using the cigarette filter. Just like the fibers, the filter paper also needs to be able to withstand the heat resulting from burning the tobacco rod. Further, in some preferred embodiments, very little water resistant chemical is used in the pulp when making the filter paper, as this allows the filter paper to absorb more moisture and increase the biodegradation process after the cigarette filter has been used. Many different types of filter papers that fulfill these criteria are known to those having ordinary skill in the art. One example would be conventional teabag filter paper. The filter paper may come in different degrees of brightness, but typically it is preferred that the filter paper is as bright as possible, in order to achieve a look that is similar to conventional cigarette filters.

The wrap paper is used to hold the two cylindrical filter paper tubes together, as will be described in further detail below. While conventional wrap paper can be used for this purpose, a thinner paper may be even more beneficial, as it allows a quicker degradation of the cigarette filter after disposal.

The glue serves to adhere the cylindrical filter paper tubes to the wrap paper. The glue can either be applied separately or be pre-applied to the wrap paper to render the wrap paper self-adhesive. In one embodiment, the glue is water-soluble, as this allows moisture in the air break loose the bonding agent if left exposed over a period of time. However, if water-soluble glue is not available, other types of glue that may also be used, although with potentially worse results in terms of biodegradability.

An exemplary process for assembling a cigarette filter in accordance with one embodiment will now be described with reference to FIGS. 1-4. FIG. 1 shows two filter paper tubes 102 and 104. At the outset, both filter paper tubes are empty, as shown in filter paper tube 102. Typically the two filter paper tubes 102 and 104 have equal size, and each filter paper tube is approximately half the size of a conventional cigarette filter. However, it should be realized that the filter paper tubes may also have different size, such that one tube may be much shorter than the other one and acts more like a cap. Many variations can be envisioned by those having ordinary skill in the art. Typically, the diameter of the biodegradable filter would be approximately 8 mm and its length would be approximately 20-30 mm when assembled, but of course the diameter of the filter paper tubes can vary such that a good fit is obtained with respect to smoking rods of different sizes.

As can be seen in FIG. 4, first, the jute fibers are cleaned to remove impurities, step 402. The cleaned fibers are then further cleaned with some appropriate kind of detergent in order to remove oil from the fibers. Optionally, the fibers can also be bleached to whiten them, if desired. Bleaching may also kill any microbes that might be present in the fibers. As the skilled person realizes, bleach is merely one option, and there may be other chemicals having similar properties that can also be used to accomplish the same results.

Next, the fibers are rinsed with water to remove any remaining detergent and/or bleach, and the fibers are allowed to dry, step 404. Ideally, the fibers should be close to 100% dry to prevent mold.

The dried fibers are then cut into small pieces and placed in the filter tubes, step 406. Typically a size of one millimeter or even smaller is preferred, although this might vary, depending on the specific situation. The cut fibers are packed tightly into the filter tubes, typically such that they fill 90-95% of the filter tube, while at the same allowing the smoke to pass through when in use.

Next, the filter tubes are placed such that their open ends face each other, as shown in FIG. 2, and the wrap paper is wrapped around the two filter tubes to hold them together and form the final cigarette filter, as shown in FIG. 3, step 408. As was mentioned above, the wrap paper may be self-adhesive, or water-soluble glue can be applied separately to the wrap paper and/or filter tubes. The biodegradable cigarette filter is now ready to be applied to the smoke rod, using conventional techniques that are known to cigarette manufacturers.

After consumption, if a user discards the cigarette butt outside, moisture, rain, and heat will break loose the outer wrap. This will cause the filter tubes to separate from each other and expose the fibers to the environmental elements, and water and wind will disperse the fibers. Since the fibers are both natural and very small, they will be essentially invisible and the fibers quickly turn into compost. The filter paper and the wrapping paper will then decompose within short period of time depend on the weather elements. Excessive wind and heat typically speeds up the decomposing process. If consumers were to discard the used cigarette butts in water, they will break up very rapidly. Running water, such as river, may speed up the process even further.

The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. For example, various flavoring agents can be added to the filter to change the characteristics of the smoke as it passes through the filter, as is well known to those having ordinary skill in the art. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein. 

What is claimed is:
 1. A biodegradable cigarette filter, comprising: a first filter tube; a second filter tube; and a wrap paper, wherein: the first filter tube and the second filter tube each has an essentially cylindrical shape and has an open end and a closed end, and is filled with organic fibers; and the first filter tube and the second filter tube are placed adjacent to each other with their respective open ends facing each other, and the wrap paper wraps around at least part of the outside of the first filter tube and at least part of the outside of the second filter tube to hold the first filter tube and the second filter tube together.
 2. The biodegradable cigarette filter of claim 1, further comprising a glue that adheres the wrap paper to the first filter tube and the second filter tube, respectively.
 3. The biodegradable cigarette filter of claim 1, wherein the glue is water-soluble.
 4. The biodegradable cigarette filter of claim 1, wherein each of the first and second filter tubes has approximately half the length of a conventional cigarette filter.
 5. The biodegradable cigarette filter of claim 1, wherein the organic fibers have a length of approximately one millimeter or less.
 6. The biodegradable cigarette filter of claim 1, wherein the organic fibers include one or more of: corchorous fibers and cotton fibers.
 7. The biodegradable cigarette filter of claim 1, wherein the first filter tube and the second filter tube are made of filter paper.
 8. The biodegradable cigarette filter of claim 1, further including a flavoring agent.
 9. A method for making a biodegradable cigarette filter, comprising: filling a first filter tube and a second filter tube with organic fibers; placing an open end of the first filter tube such that the open end faces an open end of the second filter tube; and wrapping a wrap paper around at least part of the outside of the first filter tube and at least part of the outside of the second filter tube, such that the first and second filter tubes are held together.
 10. The method of claim 9, wherein placing a wrap paper includes gluing the wrap paper to the outside of the first filter tube and the outside of the second filter tube, respectively.
 11. The method of claim 10, wherein the glue is a water-soluble glue.
 12. The method of claim 9, further comprising washing and drying the organic fibers prior to filling the first filter tube and the second filter tube.
 13. The method of claim 9, further comprising bleaching the organic fibers prior to filling the first filter tube and the second filter tube.
 14. The method of claim 9, wherein the organic fibers have a length of approximately one millimeter or less.
 15. The method of claim 9, wherein the organic fibers include one or more of: corchorous fibers and cotton fibers.
 16. The method of claim 9, wherein the first filter tube and the second filter tube are made of filter paper.
 17. The method of claim 9, further comprising adding a flavoring agent to the biodegradable cigarette filter. 